Internal-combustion engine



March 31, 1931.

G. E. CHEDRU 1,798,967

INTBRNAL COBUSTION ENGINE Filed July 16, 1928 fl ,I I, 1

I I r ,r ZJ/ im m -m Patented Mar. 31, 1931 marren STATES GUSTAVH@ EMILE CHDRU, OF NEAUPHLE LE CHATEAU, FRANCE INTERNAL-COMBUSTI ON ENGINE Application filed July 16, 1928, Serial No. 293,132, and in Belgium July lS, 1927.

The present invention relates to specially fol-med explosion ehambers for internal conhustion engines.

One of the objects of the invention is to form the pisten and cylinder head so that the explosion chamber limited by these elements favors a more efiicient explosion wave than is obtained in motors as new constructed. f

l "nrthe"r objects will appear in the course of the detailed description now 'to be gven 'With reference to the accompanying drawing, in which the single figure represents a section passing through the spark-plug of a single cylinder of a Q-cycle engine.

lteferring to the drawing, a is the internal surface of a cylinder head comprising a coolingjcham'her b, an external wall f, and a sparlplug opening d. surface a is formed so that the greater portion thereof is hemispherical. e is a water-cooled cylinder block carrying a piston h, whose head portion includes a partially helmi-spherical surface y', and a curved surface Z intersecting surface j at ?I and formed so'asto come very close to wall a when the pistoi'is at the end of its course.

The curved surface Z is a sharply sloping ridge which, as is usual in such structures, is located adjacent to, but is spaced slightly "from, the inlet side of the cylinder, so as to direct the incoming fuel upward into the combustion chamber and to sweep out the hurnt gases into the exhaust. The surface j slopes gently towards the exhaust side of the cylinder, and is oifset from the center of the piston towards the exhaust side by reason of the presence-of 'ridge Z which occupies a part ef the inlet half of the pisten surface. The chamber tormed by walls a and j is thus off set towards the exhaust side, although its width is greater thanhalf the Width of the cylinder and one of its edges therefore lies in the inlet half of the cylinder. It will he noted that the open end of wall a is out of line with the hore in cylinder-block e. Wall ,L a .is provided with a shoulder Ic positioned so as to lie just 'outside of the edge of surface ;i when the latter is at the end of its stroke. While it will he noted that surfaces a and j are neither one exactly helm-spherical, they should be so 'formed that they limit an explosion chamber which is, as nearly as practicable, of spherical form. The assembly is completed by a gasket g and bolts (not shown) maintaining the cylinder head on block e.

.In motors constructed according to the above description, the explosive mixture is forced in a Whirl into a spherical chamber which appears to favor a rapid propagation of the explosion wave and minimum cooling of the heated gases a sphere offering a minimum of cooling surface 'for any given Volume. In practice, it is found, that higher compressions than the ordinary may be employed without danger of 'auto-ignition.

The invention is not to be taken as limited to an explosion chamber of spherical form. Obviously, surfaces a and j may be made in any concave form or only hemi-spherical in limited portions to obtain results superior to those of the cylinder head and piston of usual shape, the spherical explosion chamber representing a preferred form capable of yielding a maximum of efiiciency and power.

l V hat I claim is zi. In combination, a cylinder, a cylinder head having a downwardly concave cavity therein mounted on said cylinder, a pisten slidably mounted in said cylinder and having on its upper face a sharply sloping ridge adjacent the inlet side of the cylinder and an upwardly coneave surface having the center of the projection of the said surface on a horizontal plane ofiset from the center of the p cylinder in the direction of the exhaust side of the cylinder, said ridge fitting closely the wall of said cavity when said pisten is in its uppermost position, said cavity and said upwardly concave surface forming therebe tween when said piston is in its uppermost position a chamber, the width of said chamber being greater than half the Width of said cylinder and said chamber being offset from the center of the cylinder towards the eX- haust side thereof, and a spark plug positioned in said chamber.

2. In combination, a cylinder, a cylinder head having a downwardly concave cavity therein mounted on said cylinder, a piston slidably mounted in said cylinder and having on its upper face a sharply sloping ridge adjacent the inlet side of the cylinder and an upwardly concave surface having the center of the projection of said surface on a horizontal plane `oiset from the center of the cylinder in the direction of the exhause side of the cylg u; inder, said ridge fitting closely the wall of said cavity when said piston is in its uppermost position, said cavity and said upwardly V p concave surface forming therebetween when said piston is in its uppermost position a chamber which extends from the exhaust side of the cylinder more than half the distance towards the inlet side thereof, and a spark plug positioned in said chamber.

3. In combination, a cylinder, a cylin'der head having a downwaidly concave cavity extending as far as the exhaust side of the cylinder mounted therein on said cylinder, a piston siidably mounted in said cylinder havng on its upper face a sharply sloping ridge adjacent to but spaced from the inlet side of the cylinder adapted when the piston is in its uppermost position to fit closely the wall of said cavity,` the remainde' of the upper face of said piston being upwardly concave, where-- by said cavity and said upwardly concave portion of the cylinder- 'form when the cylinder is in its uppermost position a chamber whose one edge is formed by the meeting of the top of said ridge and the wall of said cavity and which extends from a point in the inlet half of said cylinder as far as the exhaust side of the cylinder, and a spark plug positioned in said chamber;

In testimony whereof I afix signature.

GUSTAVE EMILE HDRU. 

